1. Field of the Invention
An aspect of the present invention relates to a housing siding type portable terminal in which magnets for generating both assisting force and holding force in accordance with a user's operation of sliding a housing are provided.
2. Description of the Related Art
In a housing sliding type portable terminal, a spring and magnets are used for assistance and holding in order to make a user's sliding operation smooth.
There is a sliding mechanism using such magnets (e.g. see JP-2008-113067-A). Magnetic force in the sliding mechanism of JP-2008-113067-A will be described below.
FIG. 3 illustrates a magnetic force corresponding to FIGS. 12C and 12D and paragraph [0046] in JP-2008-113067-A. In FIG. 3, (A) shows a close position, and (C) shows an open position. A housing 204 is provided with one magnet 402. A housing 202 is provided with two magnets 404 and 406.
The center position of the magnet 402 in the one-magnet housing 204 is slid between a position P1 (close position) and a position P7 (open position) relative to the two-magnet housing 202.
In (D) of FIG. 3, respective arrows express a magnetic force in a sliding direction applied on the one-magnet housing 204 in respective positions between P1 and P7. In (E) of FIG. 3, arrows and a dotted graphic curve express a repulsive force perpendicular to a principal surface, that is, a floating force applied on the one-magnet housing 204 in respective positions between P1 and P7.
In (D) of FIG. 3, sliding force in P1 (close position) is substantially zero because the respective center positions of the magnets 402 and 404 coincide with each other. In P2 or P3, rightward force to restore the center position of the magnet 402 to P1 (close position) is generated. In P4 (intermediate position), the magnet 402 is located at a middle point between the magnets 404 and 406, and sliding force is zero. The magnet 402 in P4 is however so unstable as to be apt to move either left or right. In P5 or P6, leftward force to move the center position of the magnet 402 to P7 (open position) is generated. In P7 (open position), sliding force is substantially zero because the respective center positions of the magnets 402 and 406 coincide with each other.
When a user pushes the housing 204 against such generated sliding force so that the center position of the magnet 402 moves from P1 (close position) to the left against rightward sliding force in P2 and P3, the center position of the magnet 402 is slid to P7 (open position) via P5 and P6 by leftward sliding force and held in P7 after the center of the magnet 402 goes beyond P4 (intermediate position).
Accordingly, the user needs to push the housing 204 continuously up to a position corresponding to a half of the sliding distance. After the center of the magnet 402 goes beyond the half position, the housing 204 is abruptly slid by sliding force.
In a direction of floating force in (E) of FIG. 3, adsorbing force by which the magnets attract each other in a direction perpendicular to the principal surface is generated in P1 (close position) and P7 (open position). Floating force due to repulsion of the magnets in the direction perpendicular to the principal surface is generated in a range of from P2 to P6.
There is also a slide type portable terminal using magnets (e.g. see JP-2007-288436-A). Magnetic force concerned with a sliding mechanism disposed in JP-2007-288436-A will be described below.
FIG. 4 illustrates a magnetic force corresponding to FIG. 5 and paragraphs [0048] to [0060] in JP-2007-288436-A. In FIG. 4, (A) shows a closed state, and (C) shows an opened state. A housing 3 is provided with one magnet 21. A housing 2 is provided with three magnets 8A, 8B and 8C. Magnetic poles of the respective magnets on facing sides of the housings are put in parentheses.
The center position of the magnet 21 in the one-magnet housing 3 is slid between a position P1 (close position) and a position P7 (open position) relative to the three-magnet housing 2. In (D) of FIG. 4, arrows express a magnetic force in a sliding-direction applied on the one-magnet housing 3 in respective positions between P1 and P7. In (E) of FIG. 4, directions of arrows and a dotted graphic curve express a repulsive force in a direction perpendicular to the principal surface, that is, a floating force applied on the one-magnet housing 3 in respective positions between P1 and P7.
(D) of FIG. 4 is substantially the same as (D) of FIG. 3 except that sliding force is generated in P1 (close position) and P7 (open position) in (D) of FIG. 4. Sliding force in P3 or P5 in (D) of FIG. 4 is smaller than that in (D) of FIG. 3 because the magnet 21 is slid in the long magnet 8B.
When the user pushes the housing 3 against such generated sliding force so that the center position of the magnet 21 moves from P1 (close position) to the left against rightward sliding force in P2 and P3, the center position of the magnet 21 is slid to P7 (open position) via P5 and P6 by leftward sliding force and held in P7 after the center of the magnet 21 goes beyond P4.
Accordingly, the user needs to push the housing 3 continuously up to a position corresponding to a half of the sliding distance. After the center of the magnet 21 goes beyond the half position, the housing 3 is abruptly slid by sliding force.
Floating force in (E) of FIG. 4 is as follows. Adsorbing force by which the magnets attract each other in a direction perpendicular to the principal surface is generated in P1 (close position) and P7 (open position). Floating force due to repulsion of the magnets in the direction perpendicular to the principal surface is generated in a range of from P2 to P6.
According to JP-2008-113067-A and JP-2007-288436-A, user-friendliness in sliding operation is poor because the user needs to push the housing continuously up to a position corresponding to a half of the sliding distance when the user wants to slide the housing. Moreover, because the housing is abruptly slid by sliding force after the center of the magnet goes beyond the half position, there is a problem that shock at stopping of the housing is so large that the shock has to be absorbed sufficiently. In addition, because adsorbing force is generated in a direction perpendicular to the principal surface, the user feels unsmoothness in performing sliding operation.